A boot-band is used for fixing onto a metallic member a boot that is hooked between metallic members such as a power-transmission shaft. It is used, for example, for a constant-velocity joint and the like of an automobile. In a constant-velocity joint of an automobile, a boot is hooked between shafts while holding grease inside, and the boot is clamped from the outside by the boot-band and brought into close contact with the shaft in order to prevent the grease from flowing outside between the boot and the shafts.
Because such boots, shafts, and boot-bands might have dimensional errors at the time of manufacturing, the tolerance thereof needs to be made acceptable. A boot-band that has acceptable tolerance is disclosed in Japanese Unexamined Published Patent Application No. H8-170773. An opening that extends in the longitudinal direction of a band body is punched into this boot-band. Because the cross-sectional area is reduced at the portion formed with said opening, resistance against elastic elongation under a tensile load is decreased at the time of clamping. That is to say, the opening-formation part of this boot-band is elastically deformed and elongated by clamping, and tolerance is adjusted by elongation of said opening-formation part at this elastic area.
However, when a boot-band such as that described in Japanese Unexamined Published Patent Application No. H8-170773 is elongated at the elastic area, the load on the boot is increased, as a result of which the boot might be excessively clamped and might even be broken.
Because the boot-band is elongated at the elastic area, the opening needs to be elongated in order to secure a wide range of tolerance-adjustment capability. However, because adhesiveness to the boot is reduced at the opening-formation part when the opening is made long, the clamping force at the opening-formation part is insufficient, and as a result the sealing property is deteriorated and grease leakage occurs, which creates problems.
As described above, a conventional boot-band only adjusts tolerance, and it can neither prevent breakage of the boot nor provide a stable and secure sealing. In consideration of such problems of the prior art, one objective of this invention is to provide a boot-band that not only can adjust tolerance, but that also can secure stable sealing while preventing breakage of the boot.